Surface  |  API reference  |  Android Developers (original) (raw)

public class Surface
extends [Object](/reference/java/lang/Object) implements[Parcelable](/reference/android/os/Parcelable)

Handle onto a raw buffer that is being managed by the screen compositor.

A Surface is generally created by or from a consumer of image buffers (such as a[SurfaceTexture](/reference/android/graphics/SurfaceTexture), [MediaRecorder](/reference/android/media/MediaRecorder), or[Allocation](/reference/android/renderscript/Allocation)), and is handed to some kind of producer (such as[OpenGL](/reference/android/opengl/EGL14#eglCreateWindowSurface%28android.opengl.EGLDisplay,%20android.opengl.EGLConfig,%20java.lang.Object,%20int[],%20int%29),[MediaPlayer](/reference/android/media/MediaPlayer#setSurface%28android.view.Surface%29), or[CameraDevice](/reference/android/hardware/camera2/CameraDevice#createCaptureSession%28android.hardware.camera2.params.SessionConfiguration%29)) to draw into.

Note: A Surface acts like a[weak reference](/reference/java/lang/ref/WeakReference) to the consumer it is associated with. By itself it will not keep its parent consumer from being reclaimed.

Summary

Constants

CHANGE_FRAME_RATE_ALWAYS

public static final int CHANGE_FRAME_RATE_ALWAYS

Change the frame rate even if the transition is going to be non-seamless, i.e. with visual interruptions for the user. Non-seamless switches might be used when the benefit of matching the content's frame rate outweighs the cost of the transition, for example when displaying long-running video content.

Constant Value: 1 (0x00000001)

CHANGE_FRAME_RATE_ONLY_IF_SEAMLESS

public static final int CHANGE_FRAME_RATE_ONLY_IF_SEAMLESS

Change the frame rate only if the transition is going to be seamless.

Constant Value: 0 (0x00000000)

FRAME_RATE_COMPATIBILITY_AT_LEAST

public static final int FRAME_RATE_COMPATIBILITY_AT_LEAST

The surface requests a frame rate that is at least the specified frame rate. This value should be used for UIs, animations, scrolling and fling, and anything that is not a game or video. For video, use [FRAME_RATE_COMPATIBILITY_FIXED_SOURCE](/reference/android/view/Surface#FRAME%5FRATE%5FCOMPATIBILITY%5FFIXED%5FSOURCE) instead. For game content, use[FRAME_RATE_COMPATIBILITY_DEFAULT](/reference/android/view/Surface#FRAME%5FRATE%5FCOMPATIBILITY%5FDEFAULT).

Constant Value: 2 (0x00000002)

FRAME_RATE_COMPATIBILITY_DEFAULT

public static final int FRAME_RATE_COMPATIBILITY_DEFAULT

There are no inherent restrictions on the frame rate of this surface. When the system selects a frame rate other than what the app requested, the app will be able to run at the system frame rate without requiring pull down. This value should be used when displaying game content, UIs, and anything that isn't video. In Android version [Build.VERSION_CODES.BAKLAVA](/reference/android/os/Build.VERSION%5FCODES#BAKLAVA) and above, use[FRAME_RATE_COMPATIBILITY_DEFAULT](/reference/android/view/Surface#FRAME%5FRATE%5FCOMPATIBILITY%5FDEFAULT) for game content. For other cases, see [FRAME_RATE_COMPATIBILITY_FIXED_SOURCE](/reference/android/view/Surface#FRAME%5FRATE%5FCOMPATIBILITY%5FFIXED%5FSOURCE) and[FRAME_RATE_COMPATIBILITY_AT_LEAST](/reference/android/view/Surface#FRAME%5FRATE%5FCOMPATIBILITY%5FAT%5FLEAST).

Constant Value: 0 (0x00000000)

FRAME_RATE_COMPATIBILITY_FIXED_SOURCE

public static final int FRAME_RATE_COMPATIBILITY_FIXED_SOURCE

This surface is being used to display content with an inherently fixed frame rate, e.g. a video that has a specific frame rate. When the system selects a frame rate other than what the app requested, the app will need to do pull down or use some other technique to adapt to the system's frame rate. The user experience is likely to be worse (e.g. more frame stuttering) than it would be if the system had chosen the app's requested frame rate. This value should be used for video content.

Constant Value: 1 (0x00000001)

ROTATION_0

public static final int ROTATION_0

Rotation constant: 0 degree rotation (natural orientation)

Constant Value: 0 (0x00000000)

ROTATION_180

public static final int ROTATION_180

Rotation constant: 180 degree rotation.

Constant Value: 2 (0x00000002)

ROTATION_270

public static final int ROTATION_270

Rotation constant: 270 degree rotation.

Constant Value: 3 (0x00000003)

ROTATION_90

public static final int ROTATION_90

Rotation constant: 90 degree rotation.

Constant Value: 1 (0x00000001)

Fields

Public constructors

Surface

public Surface (SurfaceControl from)

Create a Surface associated with a given [SurfaceControl](/reference/android/view/SurfaceControl). Buffers submitted to this surface will be displayed by the system compositor according to the parameters specified by the control. Multiple surfaces may be constructed from one SurfaceControl, but only one can be connected (e.g. have an active EGL context) at a time.

Public methods

clearFrameRate

public void clearFrameRate ()

Clears the frame rate which was set for this surface.

This is equivalent to calling [setFrameRate(float, int, int)](/reference/android/view/Surface#setFrameRate%28float,%20int,%20int%29) using 0 forframeRate.

Note that this only has an effect for surfaces presented on the display. If this surface is consumed by something other than the system compositor, e.g. a media codec, this call has no effect.

describeContents

public int describeContents ()

Describe the kinds of special objects contained in this Parcelable instance's marshaled representation. For example, if the object will include a file descriptor in the output of [writeToParcel(Parcel,int)](/reference/android/os/Parcelable#writeToParcel%28android.os.Parcel,%20int%29), the return value of this method must include the[CONTENTS_FILE_DESCRIPTOR](/reference/android/os/Parcelable#CONTENTS%5FFILE%5FDESCRIPTOR) bit.

isProducerThrottlingEnabled

public boolean isProducerThrottlingEnabled ()

Check if CPU throttling is enabled.

isValid

public boolean isValid ()

Returns true if this object holds a valid surface.

lockCanvas

public Canvas lockCanvas (Rect inOutDirty)

Gets a [Canvas](/reference/android/graphics/Canvas) for drawing into this surface. After drawing into the provided [Canvas](/reference/android/graphics/Canvas), the caller must invoke [unlockCanvasAndPost(Canvas)](/reference/android/view/Surface#unlockCanvasAndPost%28android.graphics.Canvas%29) to post the new contents to the surface.

lockHardwareCanvas

public Canvas lockHardwareCanvas ()

Gets a [Canvas](/reference/android/graphics/Canvas) for drawing into this surface. After drawing into the provided [Canvas](/reference/android/graphics/Canvas), the caller must invoke [unlockCanvasAndPost(Canvas)](/reference/android/view/Surface#unlockCanvasAndPost%28android.graphics.Canvas%29) to post the new contents to the surface. Unlike [lockCanvas(Rect)](/reference/android/view/Surface#lockCanvas%28android.graphics.Rect%29) this will return a hardware-accelerated canvas. See the unsupported drawing operations for a list of what is and isn't supported in a hardware-accelerated canvas. It is also required to fully cover the surface every time [lockHardwareCanvas()](/reference/android/view/Surface#lockHardwareCanvas%28%29) is called as the buffer is not preserved between frames. Partial updates are not supported.

readFromParcel

public void readFromParcel (Parcel source)

release

public void release ()

Release the local reference to the server-side surface. Always call release() when you're done with a Surface. This will make the surface invalid.

setFrameRate

public void setFrameRate (float frameRate, int compatibility, int changeFrameRateStrategy)

Sets the intended frame rate for this surface.

On devices that are capable of running the display at different refresh rates, the system may choose a display refresh rate to better match this surface's frame rate. Usage of this API won't introduce frame rate throttling, or affect other aspects of the application's frame production pipeline. However, because the system may change the display refresh rate, calls to this function may result in changes to Choreographer callback timings, and changes to the time interval at which the system releases buffers back to the application.

Note that this only has an effect for surfaces presented on the display. If this surface is consumed by something other than the system compositor, e.g. a media codec, this call has no effect.

setProducerThrottlingEnabled

public void setProducerThrottlingEnabled (boolean enabled)

Control CPU throttling for Vulkan/EGL producers.

By default Vulkan and EGL producers are CPU throttled when they queue a buffer and the consumer is still processing the previous buffer. In practice, it means that eglSwapBuffers() or vkPresentKHR() calls will stall the CPU until the GPU is done processing the previous frame. This API allows to disable this throttling while queueing a buffer.

While the default it to have throttling enabled, the more correct and efficient behavior is to have it disabled. Unfortunately, some Vulkan applications may inadvertently rely on this stall which effectively behaves as consumer/producer synchronization, albeit, inefficiently. It is therefore recommended to always disable throttling and perform proper synchronization in Vulkan.

If the CPU produces frames faster than the GPU, natural throttling will happen when a buffer is dequeued, based on the size of the queue. This typically happen during the first drawing in OpenGL ES and in vkAcquireNextImageKHR() in Vulkan.

This API has no effect in asynchronous mode, where throttling is always enabled.

toString

public String toString ()

Returns a string representation of the object.

unlockCanvas

public void unlockCanvas (Canvas canvas)

This method was deprecated in API level 17.
This API has been removed and is not supported. Do not use.

unlockCanvasAndPost

public void unlockCanvasAndPost (Canvas canvas)

Posts the new contents of the [Canvas](/reference/android/graphics/Canvas) to the surface and releases the [Canvas](/reference/android/graphics/Canvas).

Protected methods

finalize

protected void finalize ()

Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. A subclass overrides the finalize method to dispose of system resources or to perform other cleanup.

The general contract of finalize is that it is invoked if and when the Java virtual machine has determined that there is no longer any means by which this object can be accessed by any thread that has not yet died, except as a result of an action taken by the finalization of some other object or class which is ready to be finalized. The finalize method may take any action, including making this object available again to other threads; the usual purpose of finalize, however, is to perform cleanup actions before the object is irrevocably discarded. For example, the finalize method for an object that represents an input/output connection might perform explicit I/O transactions to break the connection before the object is permanently discarded.

The finalize method of class Object performs no special action; it simply returns normally. Subclasses ofObject may override this definition.

The Java programming language does not guarantee which thread will invoke the finalize method for any given object. It is guaranteed, however, that the thread that invokes finalize will not be holding any user-visible synchronization locks when finalize is invoked. If an uncaught exception is thrown by the finalize method, the exception is ignored and finalization of that object terminates.

After the finalize method has been invoked for an object, no further action is taken until the Java virtual machine has again determined that there is no longer any means by which this object can be accessed by any thread that has not yet died, including possible actions by other objects or classes which are ready to be finalized, at which point the object may be discarded.

The finalize method is never invoked more than once by a Java virtual machine for any given object.

Any exception thrown by the finalize method causes the finalization of this object to be halted, but is otherwise ignored.